Low luminosity Type II supernovae - IV. SN 2020cxd and SN 2021aai, at the edges of the sub-luminous supernovae class

Photometric and spectroscopic data for two Low Luminosity Type IIP Supernovae (LL SNe IIP) 2020cxd and 2021aai are presented. SN 2020cxd was discovered 2 d after explosion at an absolute magnitude of Mr = -14.02 ± 0.21 mag, subsequently settling on a plateau which lasts for ∼120 d. Through the luminosity of the late light curve tail, we infer a synthesized 56Ni mass of (1.8 ± 0.5) × 10-3 M⊙. During the early evolutionary phases, optical spectra show a blue continuum ($T\, \gt$8000 K) with broad Balmer lines displaying a P Cygni profile, while at later phases, Ca ii, Fe ii, Sc ii, and Ba ii lines dominate the spectra. Hydrodynamical modelling of the observables yields $R\, \simeq$ 575 R⊙ for the progenitor star, with Mej = 7.5 M⊙ and $E\, \simeq$ 0.097 foe emitted during the explosion. This low-energy event originating from a low-mass progenitor star is compatible with both the explosion of a red supergiant (RSG) star and with an Electron Capture Supernova arising from a super asymptotic giant branch star. SN 2021aai reaches a maximum luminosity of Mr = -16.57 ± 0.23 mag (correcting for AV = 1.92 mag), at the end of its remarkably long plateau (∼140 d). The estimated 56Ni mass is (1.4 ± 0.5) × 10-2 M⊙. The expansion velocities are compatible with those of other LL SNe IIP (few 103 km s-1). The physical parameters obtained through hydrodynamical modelling are $R\, \simeq$ 575 R⊙, Mej = 15.5 M⊙, and E = 0.4 foe. SN 2021aai is therefore interpreted as the explosion of an RSG, with properties that bridge the class of LL SNe IIP with standard SN IIP events.GV acknowledges INAF for funding his PhD fellowship within the PhD School in Astronomy at the University of Padova. MLP acknowledges support from the plan ‘programma ricerca di ateneo UNICT 2020-22 linea 2” of the University of Catania. AR acknowledges support from ANID BECAS/DOCTORADO NACIONAL 21202412. NER acknowledges partial support from MIUR, PRIN 2017 (grant 20179ZF5KS), from the Spanish MICINN grant PID2019-108709GB-I00 and FEDER funds, and from the programme Unidad de Excelencia María de Maeztu CEX2020-001058-M. LG acknowledges financial support from the Spanish Ministerio de Ciencia e Innovación (MCIN), the Agencia Estatal de Investigación (AEI) 10.13039/501100011033, and the European Social Fund (ESF) ‘Investing in your future’ under the 2019 Ramón y Cajal programme RYC2019-027683-I and the PID2020-115253GA-I00 HOSTFLOWS project, from Centro Superior de Investigaciones Científicas (CSIC) under the PIE project 20215AT016, and the programme Unidad de Excelencia María de Maeztu CEX2020-001058-M. TMB acknowledges financial support from the Spanish Ministerio de Ciencia e Innovación (MCIN), the Agencia Estatal de Investigación (AEI) 10.13039/501100011033 under the PID2020-115253GA-I00 HOSTFLOWS project, and from Centro Superior de Investigaciones Científicas (CSIC) under the PIE project 20215AT016, and the programme Unidad de Excelencia María de Maeztu CEX2020-001058-M. Y-ZC is funded by China Postdoctoral Science Foundation (grant no. 2021M691821

Detailed spectrophotometric analysis of the superluminous and fast evolving SN 2019neq

SN 2019neq was a very fast evolving superluminous supernova. At a redshift z = 0.1059, its peak absolute magnitude was −21.5 ± 0.2 mag in g band. In this work, we present data and analysis from an extensive spectrophotometric follow-up campaign using multiple observational facilities. Thanks to a nebular spectrum of SN 2019neq, we investigated some of the properties of the host galaxy at the location of SN 2019neq and found that its metallicity and specific star formation rate are in a good agreement with those usually measured for SLSNe-I hosts. We then discuss the plausibility of the magnetar and the circumstellar interaction scenarios to explain the observed light curves, and interpret a nebular spectrum of SN 2019neq using published SUMO radiative-transfer models. The results of our analysis suggest that the spin-down radiation of a millisecond magnetar with a magnetic field B 6 × 1014 G could boost the luminosity of SN 2019neq.XW is supported by the National Natural Science Foundation of China (NSFC grants 12288102 & 12033003), Scholar Program of Beijing Academy of Science and Technology (DZ:BS202002), and Tencent Xplorer Prize. AP acknowledges support from PRIN-MIUR 2022. AMG acknowledges financial support by the European Union under the 2014–2020 ERDF Operational Programme and by the Department of Economic Transformation, Industry, Knowledge, and Universities of the Regional Government of Andalusia through the FEDER-UCA18-107404 grant. Y-ZC is supported by the National Natural Science Foundation of China (NSFC, Grant No. 12303054) and the International Centre of Supernovae, Yunnan Key Laboratory (No. 202302AN360001). MF is supported by a Royal Society-Science Foundation Ireland University Research Fellowship. EC acknowledges support of MIUR, PRIN 2017 (grant 20179ZF5KS). SM acknowledges support from the Magnus Ehrnrooth Foundation and the Vilho, Yrjö, and Kalle Väisälä Foundation. TMR acknowledges the financial support of the Vilho, Yrjö and Kalle Väisälä Foundation of the Finnish academy of Science and Letters through the Finnish postdoc pool. IS is supported by fundings from MIUR, PRIN 2017 (grant 20179ZF5KS), by the PRIN-INAF 2022 project ‘Shedding light on the nature of gap transients: from the observations to the models’, and by the doctoral grant funded by Istituto Nazionale di Astrofisica via the University of Padova and the Italian Ministry of Education, University and Research (MIUR). NER acknowledges partial support from MIUR, PRIN 2017 (grant 20179ZF5KS) ‘The new frontier of the Multi-Messenger Astrophysics: follow-up of electromagnetic transient counterparts of gravitational wave sources.’, from PRIN-INAF 2022 ‘Shedding light on the nature of gap transients: from the observations to the models’, from the Spanish MICINN grant PID2019-108709GB-I00 and FEDER funds, and from the program Unidad de Excelencia María de Maeztu CEX2020-001058-M. CPG acknowledges financial support from the Secretary of Universities and Research (Government of Catalonia) and by the Horizon 2020 Research and Innovation Programme of the European Union under the Marie Skłodowska-Curie and the Beatriu de Pinós 2021 BP 00168 programme, from the Spanish Ministerio de Ciencia e Innovación (MCIN) and the Agencia Estatal de Investigación (AEI) 10.13039/501100011033 under the PID2020-115253GA-I00 HOSTFLOWS project, and the program Unidad de Excelencia María de Maeztu CEX2020-001058.With funding from the Spanish government through the "Severo Ochoa Centre of Excellence" accreditation (CEX2020-001058-M).With funding from the Spanish government through the "Severo Ochoa Centre of Excellence" accreditation (CEX2020-001058).Peer reviewe

Study of infestation of dogs with Echinococcus granulosus in the province of La Rioja, Argentina

Fil: Amaya, Juan C. Programa de Zoonosis, La Rioja; Argentina.Fil: Moreno, Nancy. Departamento de Investigaciones del Instituto Universitario de Ciencias de la Salud, Fundación Barceló; Argentina.Fil: Salmaso, Nancy. Laboratorio Bioquímico de Serología, Hospital Enrique Vera Barros; Argentina.Fil: Bazan, Eduardo. Laboratorio Bioquímico de Serología, Hospital Enrique Vera Barros, La Rioja; Argentina.Fil: Ricoy, Gerardo. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Parasitología; Argentina.Fil: Córdoba, Patricia. Dirección de Epidemiología del Ministerio de Salud Pública, La Rioja; Argentina.Fil: Santillán, Graciela I. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Parasitología; Argentina.This work was conducted in the province of La Rioja, located in northwestern Argentina. The aim of this study was to estimate the percentage of dog feces showing the presence of antigens of Echinococcus sp. in different regions of the province. A total of 269 samples of dried canine stool were taken, which were analyzed by the copro-ELISA technique. The most affected area was zone IV, which had 30.5% of positive samples. Zone I corresponding to the Capital Department of the province had 12% of positivity. In other areas, the percentages ranged between 11.4% and 14.8%. This is the first study in the province of La Rioja on the existence of this disease in dogs. The lack of control strategies has allowed the spread of echinococcosis

A seven-Earth-radius helium-burning star inside a 20.5-min detached binary

Lin, J., Wu, C., Xiong, H. et al.Binary evolution theory predicts that the second common envelope ejection can produce low-mass (0.32–0.36 M⊙) subdwarf B (sdB) stars inside ultrashort-orbital-period binary systems, as their helium cores are ignited under nondegenerate conditions. With the orbital decay driven by gravitational-wave (GW) radiation, the minimum orbital periods of detached sdB binaries could be as short as ∼20 min. However, only four sdB binaries with orbital periods below an hour have been reported so far, and none of them has an orbital period approaching the above theoretical limit. Here we report the discovery of a 20.5-min-orbital-period ellipsoidal binary, TMTS J052610.43+593445.1, in which the visible star is being tidally deformed by an invisible carbon–oxygen white dwarf companion. The visible component is inferred to be an sdB star with a mass ∼0.33 M⊙ approaching the helium-ignition limit, although a He-core white dwarf cannot be completely ruled out. In particular, the radius of this low-mass sdB star is only 0.066 R⊙, about seven Earth radii. Such a system provides a key clue in mapping the binary evolution scheme from the second common envelope ejection to the formation of AM CVn stars having a helium-star donor. It may also serve as a crucial verification binary of space-borne GW observatories such as LISA and TianQin in the future.The work of X.W. is supported by the National Natural Science Foundation of China (NSFC; Grant Numbers 12033003, 12288102 and 11633002), the Ma Huateng Foundation, the New Cornerstone Science Foundation through the XPLORER PRIZE, China Manned-Spaced Project (CMS-CSST-2021-A12) and the Scholar Program of the Beijing Academy of Science and Technology (DZ:BS202002). J. Lin is supported by the Cyrus Chun Ying Tang Foundations. C.W. is supported by the NSFC (Grant Number 12003013) and the Yunnan Fundamental Research Projects (Grant Number 202301AU070039). C.W., Z.H., X.C., Jujia Zhang and Y.C. are supported by International Centre of Supernovae, Yunnan Key Laboratory (Grant Number 202302AN360001). P.N. acknowledges support from the Grant Agency of the Czech Republic (GAČR 22-34467S). The Astronomical Institute in Ondřejov is supported by project RVO:67985815. N.E.-R. acknowledges partial support from the Research Projects of National Relevance (PRIN) for 2017 as funded by the Italian Ministry of Education, University and Research (MIUR; Grant Number 20179ZF5KS, The new frontier of the Multi-Messenger Astrophysics: follow-up of electromagnetic transient counterparts of gravitational wave sources), from the Italian National Institute for Astrophysics (INAF) through PRIN-INAF 2022 (Shedding light on the nature of gap transients: from the observations to the models), from the Spanish Ministry of Science, Innovation and Universities (Grant Number PID2019-108709GB-I00) and from the European Regional Development Fund. I.S. is supported by funding from MIUR through PRIN 2017 (Grant Number 20179ZF5KS) and PRIN-INAF 2022 (Shedding light on the nature of gap transients: from the observations to the models) and acknowledges the support of the doctoral grant funded by Istituto Nazionale di Astrofisica through the University of Padova and MIUR. A.V.F.’s group at the University of California, Berkeley, has received financial assistance from the Christopher R. Redlich Fund, Alan Eustace (W.Z. is a Eustace Specialist in Astronomy), Frank and Kathleen Wood (T.G.B. is a Wood Specialist in Astronomy), Gary and Cynthia Bengier, Clark and Sharon Winslow, and Sanford Robertson (Y.Y. is a Bengier-Winslow-Robertson Postdoctoral Fellow), and many other donors. OSIRIS was funded by GRANTECAN and the National Plan of Astronomy and Astrophysics of the Spanish Government. Some of the data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration (NASA). The observatory was made possible by the generous financial support of the W. M. Keck Foundation. We acknowledge the target-of-opportunity observations supported by the Swift Mission Operations Center. This research has used the services of www.Astroserver.org under references T4JRRH and Y75AKG and was based in part on observations obtained with the Samuel Oschin 48 inch Telescope at the Palomar Observatory as part of the ZTF project. ZTF is supported by the US National Science Foundation (NSF) under grant AST-1440341 and a collaboration including Caltech, Infrared Processing and Analysis Center (IPAC), the Weizmann Institute for Science, the Oskar Klein Center at Stockholm University, the University of Maryland, the University of Washington, Deutsches Elektronen-Synchrotron and Humboldt University, Los Alamos National Laboratory, the TANGO Consortium of Taiwan, the University of Wisconsin at Milwaukee and Lawrence Berkeley National Laboratory. Operations were conducted by COO, IPAC and the University of Wisconsin. This work has made use of data from the European Space Agency’s Gaia mission (https://www.cosmos.esa.int/gaia) processed by the Gaia Data Processing and Analysis Consortium (DPAC, https://www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. The Pan-STARRS1 Surveys (PS1) and the PS1 public science archive have been made possible through contributions by the Institute for Astronomy, the University of Hawaii, the Pan-STARRS Project Office, the Max-Planck Society and its participating institutes (the Max Planck Institute for Astronomy, Heidelberg, and the Max Planck Institute for Extraterrestrial Physics, Garching), Johns Hopkins University, Durham University, the University of Edinburgh, Queen’s University Belfast, the Harvard-Smithsonian Center for Astrophysics, Las Cumbres Observatory Global Telescope Network Incorporated, the National Central University of Taiwan, the Space Telescope Science Institute, NASA (under Grant Number NNX08AR22G issued through the Planetary Science Division of the NASA Science Mission Directorate), NSF (Grant Number AST-1238877), the University of Maryland, Eotvos Lorand University, Los Alamos National Laboratory, and the Gordon and Betty Moore Foundation. This publication makes use of data products from the WISE, which is a joint project of the University of California, Los Angeles, and the Jet Propulsion Laboratory/California Institute of Technology as funded by NASA. This publication makes use of VOSA, developed under the Spanish Virtual Observatory (https://svo.cab.inta-csic.es) project funded by MCIN/AEI/10.13039/501100011033/ through Grant Number PID2020-112949GB-I00. VOSA was partially updated using funding from the European Union’s Horizon 2020 Research and Innovation Programme (Grant Agreement Number 776403, EXOPLANETS-A).Peer reviewe